The present invention relates generally to a device for detecting the ends of a cassette tape and more particularly to a device for detecting a tape-end when the entire tape has been wound on a takeup reel or when the tape on the supply reel cannot travel further.
Tape-end detection devices known heretofore have detected the completely wound state of a tape. For example, a device in each reel hub is formed from a transparent material adapted to hold a photocell. The tape end detection depends upon whether or not light is received from a lamp positioned within the cassette. However, the cassette construction becomes complicated since the photocell is mounted on the side of the recording and/or reproducing apparatus and is fitted relatively into the cassette. Moreover, since light must be detected after it has been transmitted through a relatively thick reel hub, it is inaccurate and unreliable.
In another known tape-end device, a photocell is disposed outside of the reel. The light from a lamp is shut off by the tape roll wound upon the reel hub. When the tape has been completely unwound and paid out, the light from the lamp reaches the photocell. However, since a tape is very thin, there is difficulty of positively detecting whether or not the tape has been wound around the reel hub.